Glass feeder



Patented yAug. 4, i936 TENT FFICE GLASS FEEDER Frank Il. 0. Wadsworth,Pittsburgh, Pa., assigner to Ball Brothers Company, Muncie, Ind., acorporation of Indiana Application August 28, 1933, Serial No.6 87,044

35 Claims.

My invention relates to an automatic glass feeder of theself-controlled-continuous-forcedflow type, which is broadlydifferentiated from the usual forms or species of flow feeding' devicesby its capacity to establish and maintain an uninterrupted llow ofsubstantially greater volume than can be obtained either by the actionof gravity alone-as in natural flow feeders-or by the combined action ofgravity and of an intermittently applied and periodically reversedforceas in reciprocating plunger and pressure-vacuum air types ofapparatus-and one of the principal objects of my improvements is to thusgreatly augmentthe rate of delivery of the molten material, both byincreasing the mean effective eX- trusion pressure thereon, and by alsoeliminating the loss of time (and theother diiiculties) which isoccasioned by the periodic stoppage and reversal` of theexpulsionmovement thereof.

My improved type of feeder is further differentiated from those now incommon use by its capacity to control its own action in such manner asto obtain a uniformity of operative performance, and secure apreadjusted or predetermined character of delivery, that is best adaptedto produce a series of mold charges of the proper contour and weight forsubsequent fabrication in they forming machine with which the feeder isto be used; and another important purposeof the present invention is toprovide a method and a means of procedure whereby these results may beeifectively attained under a Wide variation in operative conditions.

Another object of my improvements is to pro- 2-.3 vide means forperiodically varying and controlling the extrusion pressure-and theresultant rate of discharge oi the molten glass-for the purpose o1"shaping successive sections of the continuously flowing stream (withoutinterrupt- 4;) ing the continuity of flow), prior to its separation intomold charges; and thereby obtaining a uniform series of progressivelyformed gobs or masses of material that may be readily severed from theoncoming stream (preferably at points .5 of reduced diameter) anddelivered to the receiving apparatus in the best condition for thedesired treatment therein.

A further purpose of these improvements is the provision of readilyadjustable instrumentalities for manually regulating the relativevariations in the rate-of delivery of the continuously flowing materialduring diierent portions oi each complete cycle of gob formation; andthus changing, when desired, the form or contour of successive streamsections, Without altering the mass or volume of the series of moldcharges cut,y therefrom.

Still another object of this invention is the pro--` visionV of aspecial form of delivery orifice ring, which isV particularly adapted tocooperate with 5 other'features of 'my improved feeder construction insecuring' the results that are characteristic of the combination as awhole; ory which may be used with advantage in conjunction with otheranalogous forms of apparatus.

Additional purposes and objects of the herein described improvementswill become apparent, to those skilled in this art, from a considerationof the two exemplary embodiments thereof, which are illustrated in theaccompanying drawings, and 15 in which:

Figure I is a longitudinal vertical section through the center of oneform of my improved feeder assembly;

Fig. II is a horizontal section (on a reduced scale), on the doubleplane II-II-II of Fig. I;

Fig. III is a partial vertical section, in the plane of Fig. I, whichillustratesan alternative construction of certain parts of theapparatus;

Fig. IV is a central vertical section-similar to that, of Figi-through asecond illustrative embodiment of this invention;

Fig. V is a partialv plan view-on the plane VV--V of Fig. IV--of aportion of the construction shown in-k FiglIV;

Fig. VI is a reduced scale section on the horizontal plane VI-VI of Fig.IV;

Fig. VII is a second horizontal section on the plane VII-VII of Fig. IV;andv Fig. VIII is arvertical section, in the plane of Fig.y IV, showinga slight modication of a part of the construction depicted in thatligure. n

Referringiirst to the illustrations of Figs. I, II and III; l indicatesa. forehearth, which extends out from'l the front of a suitable glassmelting 4.0 tank (not here shown), and which is` conveniently enclosedby a sheet metal boot r2, that is supported, at its outer end, byvertical posts or standards 3 3. The forward portion of the forehearthchamber (C) is provided with aV removable bell B, which is insertedthrough the iloor of the forehearth, and is held up, in sealedengagement with the roof block 4, by means of a support plate 5 and thebolts 5 6; and the lower end of this bell is partially closed by aflanged .i0 metal ring l, which is held in position by the collar 8 andan insulating bushing 9, of asbestosbre or equivalent material, andwhich forms the delivery (ilow) orifice of the feeder. The upper end ofthe bell B is cylindrical in outline, but the lower 35 part is ofrectangular shape, and is provided, on its rear side, with an upwardlytapered and transversely curved portion I0, which is recessed to form alateral extension II of the bell chamber D. The lower end of the recessII terminates in a curved port or supply passage G, which passes throughthe wall of the bell B, and is in registry with a notch in the. adjacentside of a second bell member I2 that is inserted through the roof of theforehearth I and is held down against the oor of the chamber C by theplate and bolt elements I4-I5-I5, etc. The member I2 is hollowed out toform an accumulation chamber J, which is in communication with themolten glass in the forehearth extension through the side ports I-I-I-I,and the upper end of this member is provided with a tubular bolt I6, or"nichrome, or other suitable alloy, which extends up throughV the plateI4 and terminates in a central cup I1 thereon. The port G is controlledby a reciprocable plug valve I8, which extends through the roof block 4,and which is rigidly secured tothe metal collar I9 by the bolt 2U. Thecentral stem of the collar I9 is closely engaged by a graphite orasbestos packing gland sleeve 2 I, which is mounted in the lower head ofa cylinder 22,` that is bolted to the roof plate of the forehearth boot2; and the upper end of this stem is secured, by the stud bolt 24, tothe piston 25, which is adapted to slide in the upper portion of thesaid cylinder.

The space below the lower head of the cylinder 22-which is in opencommunication with the segregation chamber D in the bell B-is connected,by the pipe 25, withthe valve chamber of a reciprocable needle valveelement 21 that is adapted to regulate the flow of compressed air fromthe conduit 28 to the chamber D; and the space above the piston 25 isconnected, by the pipe 30, with the box of a double acting piston valve3l, which serves to alternately establish communication between the saidpiston chamber and the pressure and vacuum conduits 32 and 33. Thisdouble acting valve assembly, is also coupled, by the pipe 35, to thecup I1, which communicates with the collection chamber J, and furtherserves to alternately connect the vacuum and pressure lines 33 and 32 tothe said chamber J.

The reciprocable valve elements 21 and 3l are positively moved in onedirection by the rotating cams 35 and 31 (which are mountedon a commondriving shaft but which may be angularly adjusted with respect to eachother); and areV moved in the reverse direction by the return springs 38and 39. The stem 4I) of the needle valve 21 is pivotally connected tothe lower end of a cam lever 4I which is fulcrumed on an adjustable pin42 that may be moved up and down (in the slotted extremity of the lever4I) to alter the throw of the valve head 21; `and the degree of openingof the valve-for any given setting .of the pin 42-may also beindependently varied by the axial adjustment of the threaded Valvesleeve 43 through which the inner end of the valve stem d@ passes. Theouter end of this stem carries a disc valve 45, which is normallyheldclosed by a light spring 45, but which is adapted to be engaged, andopened, by an adjustable collar 41 on the stem 4S, when the valve head21 is moved to its closed position by the return spring 38.

The functional operation of the above described parts is as follows:When the valve control elements are in the positions shown in full linesin Figs. I and II the Vupper end of the cylinder 22 is in communicationwith the compressed air line 32; the connected piston and plunger valveelements 25 and I8 are depressed until the adjustable stop nut 50, onthe upper end of the stud bolt 24 is engaged by the upper head of thecylinder 22; and the supply port G is thereby substantially closed. Thecompressed fluid then ad- 5 mitted to the upper end of the chamber D(through the pipe and valve connections 28- 43-21-26, etc.) supplementsthe action of gravity in expelling the molten glass from the orice F, ata rate which is determined and controlled by the line pressure in theconduit 28, and by the adjustment of the valve elements 42, 43 etc., andalso, if desired, by the setting of the hand valve 5I. During this stageof the operation the line 35 which leads from the accumulation cham- 15ber J is connected to the vacuum conduit 33; and the reduction inpressure in this chamber draws the glass from the orehearth pool,through the inlet ports H, H, and rapidly raises the level of the moltenmaterial in the interior of the bell I2. 2O In order to definitely limitand preadjust the volume of glass thus admitted to the accumulationchamber, I provide an automatically operated check valve 52 (or 52a Fig.III), which acts to close the lower end of the pipe 35 when the 25 glasshas reached a predetermined level, and thus arrests the further actionof the vacuum (suction) on the inilowing material. In the constructionshown in Fig. I this automatic closure of the check valve (52) iseffected by a float 55, of clay 30 or other suitable material, which isadjustably connected to the valve 52Yby a threaded stem 55, that passesloosely through the opening in the tubular bolt I6. When the valve isclosed by the lifting of the float 55, a hydrostatic balance is at 35once established between the glass within and without the bell I2; andthe elevated column of glass will remain in equilibrium in thenowvcompletely closed chamber (J) until the cam 31 acts to lift thepiston valve 3|.

In the arrangement shown in Fig. I the cams 36 and 31 revolve in aclockwise direction; and these revolving elements are preferably soadjusted that the valve 21 will be momentarily closed-thus cutting offthe application of pressure to the glass in the delivery chamber Dbefore the valve 3i is lifted by the cam 31. The reduction in pressureon the glass above the delivery orice will diminish the rate ofextrusion therefrom, and will produce a natural fnecking of theoutiowing stream, without interrupting the continuity of its movement;and the degree of this necking action can be reguiated and controlled,by the length of the depressed portion of the ciam 35, and also by theadjustment of the collars 41 which determine the amount of ventingaction effected by the relief valve 45. Concurrently with, orimmediately subsequent to, the establishment of this temporarilydecreased pressure in the chamber D the valve 3I is raised to its upperposition, by the cam 31, and the vacuum line 33 is thus put incommunication with vthe top of the cylinder 22 (through the valve port51 and the pipe 3b), while the pressure conduit 32 is concurrentlyconnected to the line 35 through the 6fvalve port 53. The exhaustion ofthe air from the space above the piston 25, permits the latter to belifted, by the unbalanced pressure of the atmosphere on its lower side,until the end 0.5 the piston bolt 25 engages the adjustable stop screw5B, and thereby opens the supply passage G by a predetermined amount.The simultaneous admission of compressed to the pipe line 35 opens theclosed check vialve 52, and thus subjects the glass in the chamber J toa predetermined pressure, (whichmay be adjusted and controlled by thehand valve iii) that will force it, through the passage G, into thesegregation or delivery chamber D, more rapidly than it can escapetherefrom throughl the delivery orifice F, and will therefore quicklyraise the level of the glass therein;-this result being effected bymaking the area of the passage G substantially greater than that of thetwo inlet ports I-I-I-I, and also greater than that of the deliveryorifice F, and by also so adjusting the valve controls 21-42-43- 5I and6l, that the pressure in the line 2S is substantially less (at thisstage in the cycle of operation) than that in the line 35.

In order to further control the automatic action of the feeder I haveprovided means whereby the valve 3l is returned to its normal full lineposition of Fig. I (independently of the movement of the cam Si), whenthe gllass has risen to a predetermined level in the delivery chamber D.As shown in Fig. I this means comprises a pair of contact rods $52 and63, one of which (62) is adjustably mounted (for up and down movement)in an insulated bushing 'eii on the base of the cylinder member 22; andthe other of which is fixed in an insulated block 65, that is secured tothe floor of the forehearth boot These contact rods are connected, bythewires and 6l, to the terminals of a magnet coil which is in serieswith a battery (or other suitable source of electric current) lil; andwhich is adapted (when energized) to act on a soft iron armature Il,that is carried on a bell crank lever and is normally held away from thecoil by the spring i3. The vertical arm of the bell crank lever 12carries a stop pawl lli, which is adapted to engage the lower end of thevalve stem 345, when the valve 3l is lifted by the cam 3?, and to holdit in its lifted position after the naised portion of this cam haspassed under and beyond the contact roller of the cooperating cam leverM. But as soon as the rising column of glass in the chamber D comes intocontact with the lower end of the rod 62 the battery cir-cuit throughthe elements 62- 66-58-61-65-63 is closed; and the armlature 'H is drawndownward and disengages the pawl 'M from the valve stern 365'; thuspermitting the valve ii to be returned to its initial full line positionby the spring This return movement again admits compressed air to thetop of the cylinder 22 (therebydepressing the plug valve i8 and closingthe passageway G) and applies vacllum to the chamber J to recharge thelatter with a fresh supply of glass.

It will be apparent that the above described assembly Yof operativeparts constitutes a selfcontrolled system, in which the volume of glassthat is dnawn into the accumulation chamber J is automatically regulatedby the adjustment or setting of the iioat with respect to the checkvalve 52; and in which the amount of molten material, that istransferred from this chamber J to the chamber D, also automaticallylimited by the Vertical adjustment of the contact rod 62; and that thetermination of these charging and transfer movements of the glass is inno way dependent uponvthe mechanica?. action of the cam 31 land of itsassociated parts. This automatic self-control of the alternate vacuumand pressure actions on the glass in the chamber J permits the use of avery high vacuum during the accumulation period (which will in turnpermit the use of relatively small inlet ports I-,I-I-I) and 'also theuse of a high pressure during the transfer period-which will result in avery rapid recharging of the delivery chamber D-without any danger ofunduly prolonging either of these operations and without requiring anyexact timing, or adjustment of the cam Si. The only func,-

'tion performed by the latter is that of initiating;

the transfer movement of the glass from the previously filledl chamber Jto the partiallyy emptied chamber D.

It will also be apparent that the total volume of,A` glass dischargedfrom the delivery orifice during any one complete cycle of operativeaction-i. e.,I during each complete revolution of the cam as-` sembly36-3D-is controlled in part by the combined gravity and air pressure onthe mass of glass above thedelivery orice F, and in part bythe degree ofthrottling exercised by the plunger Valve i8 (which may be regulated bytheI adjustmentr of the stop elements 5@ and et); and that the relativerate of extrusion of the molten material at successive intervals duringeach com-. plete cycle may also be varied and predetermined,

- by the adjustments of the valve elements .'l--li3--.

hearth chamber, and thus preventing the forma,-` tion of stagnant poolsof material, and of local;- ized Zones of varying, or variable,temperature, This circulatory movement is produced by a rotatingmulti-{2)-lobed paddlewheel 11, of suit- I able refractory material,which is mechanically keyed to the inner end of a large hollow shaft ofheat resistant metal (e. g. nichrome) that is re,- Volvably mounted in agraphite bushing 18 and is driven, from any suitable source of power, bythe sprocket wheel and sprocket chain element 'M -8D. The rotation ofthis lobed wheel maintains a continuous current flow of molten glass inone direction-e. g. a counter-clockwise ow around the front of the bellB-and a reverse circulation of the heated gases of combustion above theglass surface; and this circulatory equalization effect may be assistedor supplemented, if desired, by the use of suitably position burners(not here shown) to supply additional heat to the forehearth chamber.

It is also desirable to provide means for blocking off the flow of glassto the forward end of the forehearth chamber for the purpose of removingand (or) replacing one or both of the bell members (l2-B), when thelatter have been accidentally cracked or injured. As here illustratedthis means comprises a vertically movable block 8l,-whose lower end isimmersed in the glass, and whose width is somewhat greater than the gapbetween the inner ends of the two baliie or bridge blocks 82-82, thatproject laterally from the side walls of the forehearth chamber. Theupper end of the vertically movable gate 8l extends up through the roofof the forehearth, and is preferably covered by a removable cap 83,which is bolted to the top plate of the boot' 2, and which serves toprevent any outflow of hot gases through the opening for the member 83.

The vertical adjustment of this gate--either for F bers l2-B, and theadjacent walls of the fore-l .f

in, andto, the block 8|.

Fig. III illustrates another means for arresting the withdrawal of airfrom the-accumulation chamber J when the glass therein has risen to apredetermined level. In this arrangement the automatic closure of thevacuum line connection 35 is effected by a vertically movable disc valve52a, which is normally held open by a weighted armature 83, that ispositioned below an electro-magnet coil 89, and which is closed by thelifting of this armature when the magnet is energized. One terminal ofthis coil is connected to the battery lead 97, and the other terminal toan insulated cover nut 99 which carries a vertically adjustable threadedrod 9|, that passes down through the tubular connecting bolt 56. Whenthe rising column of glass in the chamber J comes in contact with thelower end of this rod (9|) the battery circuit is closed, through thecontact 63 (see Fig. I) and 9I,and the check valve 52a is lifted to itsseat, and is held in that position until compressed air is againadmitted to the line 35 and forces it open against the pull of theelectromagnet.

Figs. IV, V, VI, VII and VIII` illustrate another exemplaryconstruction, which presents the same general features of functionalaction and performance as are characteristic of the previously describedassembly (Figs. I to III) but which differs therefrom in certain detailsof structural form and arrangement of parts. In this structure theforward portion of the forehearth chamber (C) is provided with a raisedshelf 94, which rests on the spacing blocks 95-95, and is engaged, onits lower surface, by ya cylindrical sleeve 96, that projects up throughthe forehearth floor and is removably held in sealed contact with thesaid shelf by the plate and clamp bolt elements 5ft-6a` The spacing vblock and sleeve members -95-95 are so shaped and arranged as to form anelongated annular passageway G between the forehearth floor andthe'shelf 94, (see Fig. VII) and the latter is provided withthreeopenings 93, 99 and i539, which are respectively in registry withthe two ends of the passageway G and with the upper end of sleeve 96.

The segregation or delivery bell member B consists of a straightcylindrical sleeve'whose lower end is seated on the upper surface of theshelf block 94 and Whose upper end is engaged by the chamfered roofblock 4a, that is'held in position by the cover plate and clamp bolt.elements I 9 I-I 02 etc.;-the inner diameter, and the position, of themember B being such that its lower end embraces both of the openings 99and |99. The opening I 99, which leads from the passage G to thesegregation or delivery chamber D, is controlled by a verticallyreciprocable plug valve |8a which passes upward through the roof block4a, and is clamped at its upper end to a Vguide shaft I9a that isslidably engaged by a graphite bushing 2 Ia in the cover cap 22a.

'Ihe opening 98, in the rear part of the shelf 94, is of conical formand is covered by the lower end of a vertically reciprocable bell I2a,which is attached to the lower extremity of a guide 'rod |94, by thetubular bolt Ita and the auxiliary washer and bolt elements let-|95.This guide rod |94 is provided with a flanged collar |96, which isrigidly secured to the concentric bolt and rod members Ilia-|99, by thestud bolt and nut elements I9'l; and this collar is pivotally connected,at |98, to the inner ends of twin arm levers IDS-|99, which arefulcrumed, at II9, on

gages with a reinforcing bolt 86 that is secureda block |I| that ismounted to slide horizontally in suitable guide supports II4. The outerends of the lever arm's I99-IIJ9 are flexibly connected to the slottedhead of the guide shaft |9a by the cross bolt I|5, and carry anadjustable counterweight IIB, which serves to assist in normally holdingthe plug valve 8a in its closed position; and in concurrently holdingthe bell member I2a in its raised position. A second pair of rockingguide arms |I8-II8, are fulcrumed on xed trunnion supports IIS-H9 (whichlie in the same horizontal plane as the trunnion support III) of thelevers IBS-|99), and are pivotally connected to the levers |99 by thecross bolt |29, which is positioned midway between, and in line with,the pivot points |98 and II9. The arms II8-I I8 are also extendedinwardly, beyond the trunnion supports II9, and carry a secondadjustable counterweight IIal, which cooperates with the weight I I6 inholding the members I2a and IBa in the normal full line position of Fig.IV.

The above described system of levers and leverv connections (IIlS-II8-I99-I Ill- I I II4--II9 and HID-constitute a straight line" linkagewhich will constrain the rod |94 to move up and down in a vertical line(or at right angles to the plane of the trunnion supports IIIl-I I9),and will thus eliminate the necessity for any guide bearing for thelower end of this reciprocable member. lThe upper end of the rod issecured to a piston IZI which slides up and down in a cylinder |22 andwhich may be forced down by the admission of compressed air that isadmitted to the cylinder space above the piston through a double actingpoppet relief valve |23. The downward movement ofthe connected membersI2 I- |94 and I2a is limited by an adjustable nut 69a, whichV is carriedby the upper end of the piston rod |94; and their upward movement-(whichis accompanied by a corresponding reverse movement of the parts|8aI9a)-is controlled by an adjustable set screw 59a that is'carried bythe head 22a and is adapted to engage the counter- 4 movement of thevalve cam lever 4 la is utilized to g not only regulate the flow ofcompressed fluid to the interior of the bell B-and thereby vary andcontrol the rate of extrusion from' the delivery orifice F-but is alsoused to open the valve |23 and thereby effect the transfer of a freshcharge, or quota, of molten material from the bell chamber J to thedelivery chamber D. This action is effected as follows:

When the depressed, or cut away, portion of the revolving cam 36a passesunder the roller on the cam lever 4 Ia, the l-atter is rotated in aclockwise `direction (on its adjustable fulcrum pin support 42a) by thepull of the spring 39a; and the valve 21a is moved towards its seat bythe return spring 38a, thus momentarily reducing or relieving the airpressure in the delivery bell chamber D. The downward movement of theright hand end of the lever 4 la brings an adjustable contact screw |25into engagement with the adjacent horizontal arm of a bell crank lever|26--which is pivotally connected to the upper end of the double discpoppet valve |23-thereby closing the atmospheric exhaust port |21, andconcurrently opening the subjacent port connection to the conduit 32a.This valve movement admits compressed air to the upper end of thecylinder |22 and moves the connected piston-rodbell members|2|-||ll|-|2a downward; thereby shutting off, or throttling,com-munication between thel glass in the chamber J and the surroundingmass of glass in the forehearth chamber C, and simultaneously openingthe port connection 99 between the passageway G and the delivery chamberD. The downward movement of the hollow piston rod lllil, establishescommunication between a lateral port opening |28 in the side of this rodand the space above the piston |2|; and thereby admits compressed air tothe interior of the depressed bell d20. The pneumatic pressure thusexerted on the now confined mass of glass, in the accumulation chamberJ, forces the molten material, through the connected passages se-G-,into the segregation chamber D, at a substantially greater rate than itcan be expelled from the delivery orice F;

and this transfer or recharging action will con,-

tinue until the glass in the bell B has reached a preadjusted height,which is determined and controlled in the following manner:

A vertically adjustable contact rod 62ais passed through an asbestospacked opening in the roof block la and is projected downward into theunderlying delivery chamber D. The upper end of this rod is threaded andis engaged by a nut |30, which is rotatably mounted between insulatingcollars carried by laterally projecting lugs on the head 22a; and therod is connected, by the wire 66a, with one terminal of an electromagnetcoil 68a. A second contact rod 63ais extended through the side wall ofthe forehearth, and the adjacent portion of the spacing block 95, and isprojected into the molten glass at the front end of the passageway G(just below the opening 19) and this rod is connected, in series withthe battery 10a, with the other terminal of the coil 68a. This coil isprovided with a soft iron armature core 1la, which is normally heldinits raised position by a compression spring 13a, and which carries anupwardly projecting beveled tooth 14a, that is adapted. to engage withthe adjacent lower extremity of the-bell crank lever |26, andY lock thelatten-and the attached valve |23-in its open position; i. e., in theposition to which it is moved by the clockwise rotation of the cam leverdla. When the glass in the delivery chamber D has been raised to thelevel indicated by the dotted line in Fig. IV, the battery circuit isclosed-through the coil 68a and its connections 62a-63a66a61a etc-andthe armature 1|a is drawn down, thereby releasing the valve lever |26from the locking dog 14a, and permitting the valve |23 to be returned tothe full line (closed) position shown in Fig. IV,

lopen to the atmosphere through the restricted ,vent |32 (which isautomatically closed when the pi'ston rod A|04 is moved down), and theglass in the forehearth chamber will then flow freely intotheaccumulation reservoirthrough the large annular opening between thelower end of the raised bell and the shelf Ss-until it reaches the levelof the molten material in the main pool. But it is ofcourse possible toprovide an arrangement whereby the `vent |32 will be brought intoregistry with a port leading to a Vacuum line, When the piston rod |04is raised to cut off communication between the port |28 and the top ofthe cylinder |22, and thus apply a suction to the glass in the chamberJ, which will lift it to any desired height above the level of the glassin the forehearth chamber. Such a modified construction is shown in Fig.VIII, in which |33 is an internally grooved and radially perforatedcollar that is interposed between two packing rings, or gland members,which embrace the upper end of the piston rod |04; and 35a is a vacuumline connection which leads to an annular channel |35 that surroundsthis collar and communicates with the radial perforations therein. Whenthe first described arrangement (of Fig. IV) is used the maximum heightof glass in the accumulation chamber is determined only by the level ofglass in the main tank and forehearth extension therefrom; and this willremain constant as long as the main tank level is unchanged. With thelast described arrangement (of Fig. VIII) the maximum elevation of theglass in the bell l2a will be preferably xed and determined by mountinga vertically adjustable contact rod Qta in the tubular piston shaft lll,and utilizing this, in conjunction with the contact 63a and a suitablebattery (e. g. 1li or 10a) to close an elec'- tric circuitA through theelectromagnet coil 89a), and thereby close the cut off valve 52a, whenthe rglass in the chamber J comes in contact with the lower end of therod Sla; (see also description of the analogous control illustrated inFig. III

supra).

In order to prevent the escape ofhot gases of combustion kthrough theopening around the upper part of the vertically movable bell l2a, Ipreferably employ a.cylindrical guard sleeve |36 whose lower end isseated on the shelf block 94, and whose upper end is engaged by aflanged cap 31, that is bolted down to the cover plate llll, andisflexibly coupled to` the piston rod collar |06 jby the metallic bellows|38. The lower portion of this guard 'sleeve is cut away on the rearside (as shown in Figs. IV and VI), to afford communication between theglass in the forehearth chamber and the space surrounding the bell Iza;

but the sides of the sleeve adjacent to the forehearth walls are engagedby bridge blocks Ullill, which rest on the shelf 94 and extend above thelevel of the glass pool, so that these blocks and the interveningportion of the sleeve |36 together form a dam that cut off the flow ofmolten material to that part of the forehearth enclosure in which thebell B is mounted. In Vorder to maintain this portion of the feederassembly at the proper temperature `I provide suitable gas burners lll-@lill etc. which are preferably mounted at different levels onopposite sides of the forehearth; and are so positioned (see dottedlines of Fig. VI) as to direct op-positely moving currentsof hot gaseslaround the front of the vbell B, and rearwardly along the sides thereof,

through the openings between' the upper part of the guard sleeve and theadjacent walls, and into providing any special flues or chimneys forcarrying away the burned gases of combustion from the forehearth, andfacilitates the establishment and maintenance of uniform temperatureconditions in all parts of the forwardly advancing quotas of glass whicharesuccessivelyv supplied to the delivery chamber D and then expelledtherefrom in a continuously flowing stream.

As already stated one of the features of my present improvements is theprovision of a special form of a metal bushing or ring to define anddetermine the form and the area of the ilow orice F. The clay rings orcollars which are ordinarily used for this purpose are subject tomechanical attrition, as well as tothe solvent action of the acidsilicate constituents of the molten glass; and are also subject toinjury in the plugging and unplugging. of the flow orifice at thebeginning and the end of each weeks run; and all ofrthese actions tendto alter both the size and the shape of the opening through whichl themolten material is extruded, and thereby vary the cross sectional formor (and) the desired rate of delivery of the outiiowing stream. In orderto avoid these diiculties, and at the same time avoid any substantialcoooling of the stream surface by thermal conduction, Ivprovide a flowbushing (l or la) which has a very thin cross section, and is made ofhighly refractory metal, (e. g., nichrome or tungsten-molybdenum alloy)and insulate this ring from its collar support (8 or a) by a thickwasher (9 or 9a) of asbestos or other non-conducting material. 'Iheinternal surface of this metal bushing (1 or' la) may be accuratelymachined to. a predetermined size and shape (of either circular, orelliptical or other desired cross sectional form), and may also behighly polished; and it will very quickly become uniformly heated tosubstantially the same temperature as that of the glass in contacttherewith; so that it will not only serve to accurately determine thecontour of the stream which issues from the delivery orifice (F) but itwill also serve to diminish any retardation of the outflow by frictionalresistance or by surface chilling.

In the normal opera-tion of my improved feeder, suitable means will beprovided for severing the extruded and constantly flowing stream ofmolten material, at proper intervals, to form a succession of moldcharges; and for delivering these successively cut off masses to theforming machine. This means may comprise a pair of movable shear blades(S-Sl-such as are indicated in dotted lines in Fig. I-which are prefer-Aably positioned quite close to the lower end of the delivery orifice F,and are operated at any desired time in the cycle of feedaction-(preferably v1933, 653,081, filed Jan. 23, 1933, and 701,636,

led Dec. 9, 1933, but as this severing means forms no part of theparticular feature of improvement herein set forth (except ascomplemental thereto) no further description thereof will be given.

I desire it to be understood that I have devised Vvarious structures andprocedures `for producing and utilizing a continuously flowing stream ofmolten glassin connection with the formation of mold chargesv andvinwhichthe flow of glass through thel orifice is never less than a gravityflow under the existing head and that various details of such apparatusand such procedure here illustrated and described but not claimed hereinare claimed in my following copending applications 679,889, filed July11, l1933, 687,042, filed Aug. 28, 1933, 687,043, filed Aug. 28, 1933,716,626, filed Mar. 21, 1934, and 716,627, filed Mar. 2l, `1934.V Itwill bereadily understood, without further extended explanation, thatall of the operative portions of Ymy improved feeder assemblies are soconstructed andV arranged that they may be individually removed from theforehearth boot supports (2 and 3 or 2a and 3a) whenever it lisnecessary to replace injured or worn out parts; and that the-,variousmanual adjustments, which may be used to vary and control the feedingac,- tion, are all readily accessible to the operator in charge of theapparatus; and that these adjustments provide for Vavery wide range ofchange in the operative conditions, without aiecting the inherentself-controlled action of various cooperative elements. And with thepreceding disclosure as a guide those skilled in this art will now beable-to understand and appreciate the functional characteristics and theoperativea-dvantages of the herein described improvements; and will beable to devise various other alternative or equivalent structures whichwill be capable of practicing my present invention, and of attaining, inwhole or in part as may be desired, the various objects and results thathave been hereinbefore mentioned or are now apparent.,

What I claim is:

1. In combination in a glass feeder, aforehearth enclosing anaccumulation chamber, and

a delivery chamber, a passage between said cham*- bers, means forcontrolling the delivery of glass from said foreliearth to saidaccumulation chamber, a device for controlling said passage. and meansresponsive to the glass level within said delivery chambers forcontrolling said device.V

2. In combination in a feeder for molten material, a forehearth, anaccumulation chamber and a delivery chamber associated within saidforehearth, aV passage `between said chambers, means for controlling thedelivery of molten material from said forehearth to said accumulationchamber and from said accumulation chamber to said delivery chamber, andmeans dependent on the material level within said chambers forcontrolling said rst mentioned means.

3. In combination in a feeder for molten material, a forehearth, anaccumulation chamber and a delivery chamber associated within saidforehearth, a passage between said chambers,

means for drawing a quota of material from said' forehearth into saidaccumulationl chamber, means .responsive to material level within saidaccumulation chamber for controlling said rst lmentioned means, meansfor controlling said passage, and means responsive to material levelVwithin said delivery-chamber for controlling the operation of saidpassage controlling means.

4. In combination in a feeder for molten glass, a forehearth, anaccumulator chamber and adeivery chamber associated with saidforehearth,

`a passage between said chambers for delivering Vglass from theaccumulator to the delivery chamber, a device for controlling saidpassage, and means for operating said device toclose Said passage andfor drawing glass into said accumulator chamber while discharging glassfrom said delivery chamber.

5. In combination in a feeder for molten glass, a forehearth, anaccumulator chamber and a delivery chamber associated with saidforehearth, a passage between said chambers for delivering glass fromthe accumulator to the delivery chamber, a device for controlling saidpassage, and means for operating said device to close said passage andfor drawing glass into said accumulator chamber while discharging glassfrom said delivery chamber and means responsive to the glass levelwithin said chambers for controlling the operation of said firstmentioned means.

6. In combination in a glass feeder, a forehearth, a delivery chamberhaving a submerged flow orifice associated with said forehearth and anaccumulator chamber communicating with said delivery chamber, automaticmeans for controlling the delivery of glass from said forehearth to saidaccumulator chamber and from said accumulator chamber to said deliverychamber and means responsive to glass levels within said chambers forcontrolling said automatic means.

7. In combination in a glass feeder, a forehearth enclosing a deliverychamber having a submerged flow orifice and an accumulator chamber, asubmerged passage between said chambers, means for reciprocating saidaccumulator chamber to establish and cut off communication between saidpassage and said forehearth, and a mechanically actuated device foropening and closing said passage.

8. In combination with a forehearth for molten glass having a ow orificeassociated therewith, a closure for said forehearth, a gate extendingthrough an opening in said closure and projecting into the glasscontained within said forehearth, a shield secured to the outer surfaceof said closure and enveloping the end of said gate projecting throughsaid opening and means extending through said shield for actuating saidgate.

9. In combination in a feeder for molten glass, a forehearth enclosing adelivery chamber having a submerged iiow orifice, an accumulator, apassage between said chamber and said accumulator, means forreciprocating said accumulator, means for closing said passage and meansfor simultaneously subjecting said chamber to superatmosphericl pressureand said accumulator to sub-atmospheric pressure.

10. In combination in a glass feeder, a forehearth, a delivery chamberlocated within said forehearth and provided with a submerged floworifice, an accumulator chamber, an inverted bell mounted within saidaccumulator chamber, a passage between said chambers, a device foropening and closing said passage, and counterbalanced means forreciprocating said bell and said device.

11. In a feeder for molten glass, a forehearth, a delivery chamberlocated therein and provided with a submerged flowy orifice, anVaccumulator chamber, a submerged passage between said chambers, aninverted bell located Within the accumulator passage, a reciprocatorydevice located within the delivery chamber for controlling said passage.and associated means for liftingsaid bell as said device is lowered toclose said passage and means for simultaneously subjecting the interiorof said bell to vacuum pressure and said chamber to super-atmosphericpressure.

`12.*In combination in a glass feeder, a forehearth, a delivery chamberlocated within the forehearth and having a submerged orifice formedtherein, means for segregating a quota of glass from said forehearthwhile a previously segregated quota is discharged from said deliverychamber and means responsive to glass level within said chamber forcontrolling the delivery of segregated quotas thereto.

13. A method of delivering a succession of mold charges from a pool ofmolten glass which consists in withdrawing and segregating a quota ofglass from said pool, transferring glass from said segregated quota to aglass delivery position, controlling the amount so transferred by thelevel of `the glass in such delivery position and discharging suchtransferred portion while withdrawing and segregating a succeeding quotafrom said pool.

14. A method of delivering mold charges from a pool of molten glasswhich consists in successively withdrawing and accumulating quotas ofmolten glass from said pool, transferring a measured portion of eachsuch accumulated quota to a body of glass maintained over an open floworice and severing a mold charge from the stream flowing through suchorifice while withdrawing and segregating a succeeding quota from saidpool.

15. In combination with a forehearthhaving a discharge orifice, adelivery chamber above said orifice, an accumulator chamber and apassageway joining said chambers, means for subjecting the interior ofsaid accumulator chamber to a vacuum pressure, means responsive to theglass level within said chamber for controlling the operation of saidmeans, means for moving the glass in said accumulator chamber throughthe passageway and into said delivery lchamber, means for closing saidpassageway, means responsive to the glass level with said deliverychamber for operating said closing means, and means for subjecting theglass within the delivery chamber to super-atmospheric pressure.

16. In combination with a forehearth having a discharge orifice, adelivery chamber, an accumulator chamber and a passage joining saidchambers, means for segregating a quota of molten glass within saidaccumulator chamber, means for moving glass from the accumulator chamberthrough the passage and into the delivery chamber, means for closingsaid passage, means responsive to the glass level within said deliverychamber for operating said closing means, and means for subjecting theinterior of the delivery chamber to super-atmospheric pressure.

17. In combination with a forehearth for mol ten glass having a floworifice therein, an inverted bell projecting into said forehearth andextending below the level of glass contained therein, means forreciprcating said bell, a ported sleeve surround said bell andprojecting into the glass in said forehearth, a hollow member adjacentsaid sleeve and in communication with said bell and said orifice andmeans for alternately connecting said bell and said hollow member to asource of fluid pressure.

1S. The method of delivering molten glass from a pool of such materialwhich consists in segregating a quota of material from said pool,transferring a portion of the segregated material to a delivery postion,controlling the quantity of material so transferred by the glass levelin the delivery position, discharging said transferred material whilepreventing a reversal of fiow from 'the delivery position andsegregating another quota from said pool simultaneously with thedischarging of the transferred material.

19. The method. of delivering molten glass from a pool of such materialwhich consists in segregating a predetermined quota of material fromsaid pool, transferring a portion of the segregated quota to a deliveryposition, utilizing Athe level of material in the delivery position tocontrol the amount of segregated material transferred thereto,discharging the transferred material while preventing a reversal of flowfrom said delivery position and segregating another quota simultaneouslywith the discharge of the transferred material.

2G. A pneumatic glass feeder comprising a forehearth having a floworifice therein, a delivery chamber in communication with said floworifice, an accumulation chamber communicating with the forehearth andhaving a passage leading therefrom into said delivery chamber, a closuremember for said passage, means for alternately connecting saidaccumulation chamber to sources of fluid pressure and vacuum, means forperiodically connecting the delivery chamber to a source of fluidpressure and means for moving said closure member into passage-closingposition each time said delivery chamber is connected to the source ofpressure.

21. A pneumatic glass feeder comprising a forehearth having a flow oricetherein, a delivery chamber in communication with said flow orifice, anaccumulation chamber communicating with the forehearth and having apassage leading therefrom into said delivery chamber, a closure memberfor said passage, means for periodically connecting said accumulationchamber to a source Y of fluid pressure to move material therein throughthe passage into said delivery chamber, means for periodicallyconnecting said delivery chamber to a source of fluid pressure, andmeans operable when said delivery chamber is connected to pressure formoving said closure member into passage-closing position.

22. A pneumatic glass feeder comprising a forehearth having a floworifice therein, a delivery chamber in communication with said floworifice, an accumulation chamber communicating with the forehearth andhaving a passage leading therefrom into said delivery chamber, a closuremember for said passage, means for alternately connecting saidaccumulation chamber and Said delivery chamber to a source of fluidpressure, and means operable when said delivery chamber is connected tothe source of pressure for moving said closure member intopassage-closing position.

V23. The combination with a feeder for molten .glass comprising aforehearth having a iiow orice therein, a delivery chamber incommunication with said fio-w orifice, an accumulation chambercommunicating with the forehearth and havking a passage leadingtherefrom into said delivery chamber, .a closure member for saidpassage, means for alternately connecting the accumulation chamber tosources of vacuum and iiuid pressure to alternately accumulate aquantity of glass therein and discharge glass therefrom into saidvdelivery chamber, means for periodically moving said closure memberinto said passage-closing position, means responsive to the glass levelwithin -said delivery chamber for independently operatingsaidpassage-closure member, and means for Vperiodically connecting thedelivery chamber to a source of fluid pressure.

24. The combination in a feeder for molten glass comprising a forehearthhaving a flow orice therein, a delivery chamber in communication withsaid cw orifice, an accumulation chamber communicating with theforehearth and having a passage leading therefrom into said deliverychamber, a closure member for said passage, means for periodicallyconnecting the accumulation chamber to a source of pressure to movematerial therefrom through said passage into said delivery chamber,means responsive to the glass level within said delivery chamber forclosing the connection between said accumulation chamber and the sourceof fluid pressure, means for periodically moving said closure memberinto passage-closing position, and means for periodically connectingsaid delivery chamber to a source of fluid pressure.

25. The combination in a feeder for molten glass comprising a forehearthhaving a flow orifice therein, a delivery chamber in communication withsaid iiow orice, an accumulation chamber communicating with theforehearth and having a passage leadingftherefrom into said deliverychamber, a closure member for said passage, means for alternatelyconnecting said accumulation chamber and said delivery chamber to asourceof fluid pressure, means responsive to the glass level within saiddelivery chamber for automatically closing communication between theaccumulation chamber and the source of fluid pressure, and meansoperable when said delivery chamber is connected to the source of fluidpressure for moving said closure member into passage-closing position.

26. The combination in a feeder for molten glass comprising a forehearthhaving a flow orice therein, a bell ,projecting Vinto said forehearthand extending below the level of the molten glass contained therein, ahollow member adjacent said bell and in communication with said orice, aiioo-r block having an opening therein for establishing communicationVbetween said bell and said hollow member, a closure member for saidopening, means for reciprocating said bell and closure member, and meansfor alternately connecting said bell and said hollow member to a sourceof fluid pressure.

27. The combination in a feeder for molten glass comprising a forehearthhaving an orifice therein, a bell projecting into the forehearth andextending below the level of the molten glass contained therein, ahollow member adjacent said bell and in communication with said orifice,a floor block having an opening therein establishing communicationbetween said bell and said hollow member, a closure member for saidopening, means for reciprocating said bell and closure member, means foralternately connecting said bell and said hollow Ymember to a source offluid pressure, and means responsive to the level of glass in saidhollow member for independently closing the connection between said belland the source of fluid pressure.

28. The combination in a feeder for molten glass comprising aforehearth, a hollow member supported in said forehearth and having aflow orifice therein, a spout projecting from said member, a stationarybell adjacent said member and having a series` of ports therein o-ne ofwhich is in registration with said spout, means for alter'- natelyconnecting said bell to sources of fluid pressure and vacuum, meansresponsive to the level of glass within said bell for closing theconnection to the source of vacuum, a closure member for said spout,means for reciprocating said closure member and means operable when saidspout is closed for connecting said hollow member to a source of fluidpressure to expel the glass therefrom through the orifice.

29. The combination in a feeder for molten glass comprising aforehearth, a hollow member supported in said forehearth and having aiiow orifice therein, a spout projecting from said member, a stationarybell adjacent said member and having a series of ports therein one ofwhich is in registration with said spout, means for alternatelyconnecting said bell to sources of iiuid pressure and vacuum, meansresponsive to the level of glass within said bell for closing theconnection to the source of vacuum, a closure member for said spout,means reciprocating said closure member, means responsive to the levelci glass within said hollow member for actuating the closure memberreciprocating means, and means for periodically connecting the hollowmember to a source of iiuid pressure to expel the glass therein throughthe orifice.

30. The combination in a feeder for molten glass comprising a forehearthhaving a flow orifice therein, a delivery chamber in communication withsaid oriiice, an accumulation chamber communicating with the forehearthand having a passage leading therefrom into said delivery chamber, agate normally closing said passage, means for periodically moving saidgate to open said passage, means for applying an expelling force to theglass in said accumulation chamber to transfer glass therefrom throughsaid passage and into said delivery chamber, and means responsive to theglass level within said delivery chamber adapted to control the closingof saidV gate.

3l. The combination in a feeder for molten glass comprising a forehearthhaving a iiow orifice therein, a delivery chamber in communication withsaid oriiice, an accumulation chamber communicating with the forehearthand having a passage leading therefrom into said delivery chamber, areciprocable closure member for said passage, means for reciprocatingsaid closure member, a valve for controlling the operation of saidclosure member reciprocating means and adapted to connect saidaccumulation chamber to sources of fluid pressure, mechanical means forperiodically operating said valve and means responsive to the glasslevel in said delivery chamber for operating said valve independently ofsaid mechanical means.

32. The combination in a feeder for molten Y glass comprising aforehearth having a iiow orifice therein, a delivery chamber incommunication w'lth said orifice, an accumulation chamber communicatingwith the forehearth and having a passage leading therefrom into saiddelivery chamber, a gate for closing said passage, iiuid actuated meansforcontrolling the movement of said gate, means for introducing iiuidpressures into said accumulation chamber, a valve for controllingdelivery of fluid pressures to said iiuid actuated means and to saidaccumulation chamber, mechanical means for operating said valve andmeans responsive to the glass level with said delivery chamber foroperating said valve independently of said mechanical means.

33. The combination in a feeder for molten glass comprising aforehearth, a delivery chamber in open communication with a iloworifice, an accumulation chamber communicating with the forehearth andhaving a passage leading rtherefrom into said delivery chamber, aclosure member for said passage, fluid actuated means forreciprocatingsaid closure member, a valve for connecting alternately said iiuidactuated means and said accumulation chamber to sources of liuidpressure and vacuum mechanical means for actuating said valve, meansresponsive to the level of glass within said accumulation chamber forindependently closing its connection to the source of vacuum, meansresponsive to the level of glass within said delivery chamber foroperating said valve independently of said mechanical means, and meansfor periodically applying an expelling force to the molten glass withinsaid delivery chamber.

34. A method of forming a succession of mold charges from a mass ofmolten glass, which consists in successively withdrawing andaccumulating quotas of molten glass from said mass, transferring glassfrom each such quota to a body of molten glass maintained over a iiowoflice,while proportioning the quantity of glass so transferred inaccordance with variations in the head of glass of such body over saidorifice, yand severing mold charges from the stream issuing from saidorifice in timed relation with the accumulation of such quotas.

35. A method of forming a succession of mold charges from a mass ofmolten glass, which consists in withdrawing a quota of glass from suchmass, shutting off communication between the quota so withdrawn and saidmass and substantially simultaneously establishing communication betweensuch quota and a body of glass maintained above a iiow orifice,delivering glass from such quota to such body to increase the headthereof over said orifice, shutting off communication between said bodyand the undelivered portion of said quota, and substantiallysimultaneously establishing communication between such portion of suchquota and such mass, continuing the discharge of glass from said bodythrough said orifice while replenishing such quota and repeating thecycle while severing the stream issuing from said orifice in timedrelation with such replenishing operations.

FRANK L. O. WADSWORTH.

